Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:11:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[k].size(); i++ ) ^ user.cpp:23:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < v[k].size(); i++) ^ user.cpp:17:9: warning: unused variable ‘ss’ [-Wunused-variable] int ss = 0; ^ user.cpp:20:9: warning: unused variable ‘ok’ [-Wunused-variable] int ok = 0; ^